"So it feels very comfortable to stand here today with Joe and welcome him to the Conservative Caucus."

Comuzzi, 74, had served as a Liberal MP since 1988. The MP for the Ontario riding of Thunder Bay-Superior North becomes the first Conservative to represent the area since 1930. He has previously said he won't seek re-election.

Liberal Leader Stephane Dion kicked Comuzzi out of the Liberal caucus after he voted for the Conservatives' 2007 budget. He did so because the budget promised money for a cancer research centre that would create 300 jobs in Thunder Bay.

Comuzzi hinted his discontent with his former party ran deeper than the one vote.

"I gave 18 years to the Liberal Party. But it's not my party anymore," he said in a statement. "Mr. Dion is taking it down a road I cannot follow."

He left cabinet in 2005 so he could vote against the Liberal government's legislation to legalize same-sex marriage. He also crossed swords with the Liberals over gun registry spending and by calling for a review of official bilingualism.

Besides Comuzzi, Ontario MP Wajid Khan left the Liberals to join the Tories. Industry Minister David Emerson crossed the floor two weeks after the Jan. 23, 2006 election.

Ontario MP Garth Turner got kicked out of the Conservative caucus last year and then joined the Liberals.

The Tories recently booted out Nova Scotia MP Bill Casey, who voted against the budget because he felt it violated the province's Atlantic Accord on offshore resources. He is currently sitting as an Independent Progressive Conservative MP.

The current standings in the 308-seat House of Commons are:

Conservatives - 125

Liberals - 100

Bloc Quebecois - 49

NDP - 29

Independents - 3

Vacant - 2

Bill Graham and Jim Peterson, two long-serving Liberals, will be leaving elected office in July. Bloc MP Michel Gauthier is also expected to step down. A byelection must be called for Montreal's Outremont riding, vacated by former Liberal MP Jean Lapierre.